Fish deaths leave more questions about Macquarie Harbour oxygen levels unanswered

Greens spokesperson for Fisheries, Senator Peter Whish-Wilson provides the following comments on the salmon deaths in Macquarie Harbour.

“Last week I heard evidence from locals that a storm had caused the upwelling of dead and deoxygenated water below fish pens in Macquarie Harbour leading to millions of dollars of fish deaths.

“Now we have had it confirmed that some 270 tonnes of salmon have been killed.

“The Greens and environmentalists have warned for years that the rapid growth of the salmon industry in Macquarie Harbour was potentially a ticking time bomb due to deteriorating oxygen levels.

“This is not about the stocking rates of any one company; this is about the cumulative load of farmed salmon in the Macquarie Harbour system. Concerns have been raised that there is only so much excess nutrient load a semi-closed system like Macquarie Harbour can tolerate.

“It is a known impact of salmon farming that overstocking can overload the sea floor with waste and lead to deoxygenation of the bottom waters.

“This fish kill event is consistent with ongoing concerns about declining oxygen levels in Macquarie Harbour.

“The Tasmanian Government has a report on dissolved oxygen levels that it is refusing to release to the public.

“The Government thinks that hiding the truth from the public and attacking those with genuine concerns will help the industry.

“I am glad that an upcoming Senate Inquiry will provide an opportunity for all stakeholders to address these issues, and how they should be regulated, in an independent and transparent manner.